I personally find it a good trait because I need people to be direct with me or I simply won't get their social hints, then they get mad at me for not getting it or I get frustrated because I can sense something is off but can't tell what. People naturally do not do that though, so when you are "blunt" it's seen as abnormal. People don't like bluntness - it's seen as rude, but also people don't like to hear the truth sometimes.

Black and white thinking is as healingme4me said, it supposedly means you're inflexible and that's not "healthy". I can't really argue with that as much as I don't like the sound of it because I'm pretty broken and think a lot in black and white, but I also try to consider grey. In some cases I can see why it's bad to not see the grey areas, but in other ways it just doesn't make sense and yet I've been told that me being able to make a clear decision on which side is black and which is white is an incorrect way of thinking.